Drier felt



130, 1940- R. L. DEMPSEY- 9,87

- I DRI ER FELT Filed Oct. 5, 1939 Patented July 30, 1940 UNITED STATES PATENT OFFICE 2,209,874 .DRIER FELT Roland L. Dempsey, Fitchliurg', Mass.

Application October 5, 1939, Serial No. 298,145

1 Claim.

This invention relates to woven drier felts of the general type used in carrying moist newly formed paper pulp around and in contact with the heated drums of the paper making machinery.

One object of this invention is to provide a drier felt having greater and more uniform porosity.

Another object of this invention is to provide a drier felt wherein each of the fillers in top and bottom plies are tied into the structure of the other ply.

A further object of this invention is to provide a drier felt wherein the binder threads are closely woven to certain of the warp threads to improve the porosity of the structure.

Still another object is to provide a drier felt which will wear evenly in use.

Other objects and advantages of this invention will appear from the following description taken in connection with the accompanying drawing.

In the drawing, wherein like reference characters indicate corresponding'parts in the various figures:

Figure 1 is a partial plan view of the upper ply of a drier felt incorporating features of this inventive concept.

Figure 2 is a partial plan view of the back or bottom ply of the drier felt, the plane being taken intermediate thetwo plies.

Figure 3 is a longitudinal vertical cross-section parallel with the'warp threads and taken substantially on the line 3-3 of Figures 1 and 2.

Figure 4 is a transverse vertical cross-section through the drier felt taken line 4-4 of Figure 1.

Figure 5 is a longitudinal vertical cross-section corresponding to a view parallel to the warp threads and taken substantially on the line 5-5 of Figures 1 and 2.

The preferred embodiment of the invention as. shown presents a drier felt comprising a closely woven, even surfaced face ply l0, and a back ply II with an open weave. Figure 1, comprises the warp yarns l2 and the weft or filleryarns l3, plain woven. The back ply, Figure 2, comprises the warp yarns H and the weft or filler yarns l5, also plainwoven. The warp and weft yarns l2, l4 and I3, l5 respectively of the two plies are of about the same I weight. I construct the face and back plies with equal weft count, see Figure 3, for a purpose that will appear hereinafter. The face ply, however, has more warp yarns than the back ply. In practice and in the preferred embodiment shown,

. weave the two plies firmly.

substantially on the The faceply,-

I are alternated transversely of the fabric to pass over adjacent weft yarns in the face ply, and 10 under adjacent weft yarns in the backply. By means of this construction, each weft yarn of each ply is tied in by the binder yarns to inter- The binder yarns l6 and I! are preferably finer than the body 16 yarns l2, l3, l4 and I5, and are therefore imbedded within the weave of the respective plies without disturbing the pattern of the Weave.

In the two-to-one warp yarn arrangement betweenface and back plies, adopted for the pre- 20.

ferred embodiment shown, I arrange the warp yarns of the face ply in groups l8 and I!) demarked by the binder yarns l6 and II. The group I8 comprises three warp yarns and alternates with group IQ of one warp yarn, see Figure 4. By means of this construction, each weft yarn of the face and back plies is interwoven at intermittent points transversely of the fabric, spaced apart the extent of three warp yarns.

The fabric appears loosewoven for purposes of clear illustration. In practice, both plies are tightly woven in the process of manufacture. The back ply is tightly woven because it has as many weft yarns as the face ply. With reference to the face ply, it is tightly woven to give it strength and to afford an even, smooth surface. The back ply with its deficiency of warp yarns affords a greater flexibility and greater porosity, which porosity is uniform throughout the area of the fabric because of the paired arrangement of the binder yarns I6 and IT. The air spaces between the yarns afford more rapid drying of the felt; The surface of the drier felt does not have a multiplicity of relatively hard and high spots,

as in the well-known constructions of the prior art, wherein all of the binders pass over and under .the same filler threads in each ply. The elimination of these high spots. results in the drier felt wearing uniformly throughout, its sur- 5 In the preferred embodiment, there are twice as many warp threads in the surface ply as in the back ply, although other arrangements may be found suitable within the scope of the invention. The warp and binder threads may be made either all of cotton material or partly of other materials, either mineral, animal, or vegetable, although a preferred construction utilizes cotton threads throughout.

In view of the described construction, a drier felt is provided having uniform wear, great porosity, and other advantages, as heretofore set forth.

Although a preferred embodiment of this invention is illustrated and described, variations within the true spirit and scope of the same are to be determined by the appended claim.

What I claim is:

A woven drier felt comprising a plain woven face ply, and a plain woven back ply, weft yarn of the face ply and back ply being equal in number per unit length of felt, warp yarns of the face ply being greater in number than the warp yarns of the back ply, warp binderyarns interweaving the two plies and disposed in pairs of adjacent yarns, the yarns of each pair of binder yarns being separated by a single warp yarn of the face ply and a single warp yarn of the back ply, the pairs of binder yarns being separated by three warp yarns of the face ply and by one warp yarn of the back ply.

ROLAND L. DEMPSEY. 

